The Invention of Ecocide: Agent Orange, Vietnam, and the Scientists Who Changed the Way We Think about the Environment

The Invention of Ecocide: Agent Orange, Vietnam, and the Scientists Who Changed the Way We Think about the Environment

Excerpt

For the past four years, I have followed 2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) through history. Plant physiologists classify these synthetic chemical compounds as selective auxins of the phenoxyacetic herbicide family. They were the first plant killers developed by scientists to target specific “weeds”—any plants useless or counterproductive to human needs.

The discoveries that led to modern herbicides began in Charles Darwin’s laboratory. Late in his life, Darwin discovered that some internal mechanism directs plants to grow toward sunlight and sources of water. American and European scientists later called this mechanism the plant’s hormone system. On the eve of World War II, scientists discovered that certain chemical syntheses could enhance the growth of a plant—and in higher concentrations, kill it. Via absorption through the leaf, 2,4-D and 2,4,5-T wreak havoc on the plant’s hormones. Several days after exposure, the treated plant experiences uncontrolled and rapid growth, until its leaves shrivel back to a brown mass and fall off.

The biochemical specificity of these herbicides has no cultural analog: no universally accepted characteristics distinguish weeds from other plants. The designation depends on what people want from land they seek to control. On farms, sprayed applications of 2,4-D and 2,4,5-T can keep weeds out of cropland and animal pasture. After World War II, herbicides, along with pesticides, dramatically increased agricultural yields worldwide in what became known as the Green Revolution. The massive application of herbicides for farming, forest management, and lawn care continues today at global annual rates exceeding a billion gallons.

This book focuses on one aspect of herbicide use that is now a relic of his-